ABSTRACT
<p><b>OBJECTIVE</b>Mutations of presenilin 1 (PSEN1) gene are the most frequent cause for familial Alzheimers disease (AD). This study was set to explore potential mutation of PSEN1 gene in a Chinese family featuring early-onset Alzheimers disease (FAD).</p><p><b>METHODS</b>DNA was isolated from peripheral blood samples from 17 members of the FAD family as well as 10 patients with sporadic Alzheimers disease and 100 healthy subjects. With polymerase chain reaction (PCR) and Sanger sequencing, exons 113 of the PSEN1 gene were analyzed.</p><p><b>RESULTS</b>DNA sequencing has revealed a heterozygous point mutation from G to A at position 1133 (Gly378Glu) of exon 11 of PSEN1 gene in 6 members from the family, among whom 5 were patients with dementia, whilst the remaining 1 was clinically normal but under onset age. The same mutation was not found in all other patients and the normal controls.</p><p><b>CONCLUSION</b>A novel missense mutation of the PSEN1 gene, Gly378Glu, probably underlies the autosomal dominant early-onset FAD in this Chinese family.</p>